The In Vitro Models and Cell Culture Core is established as a resource for all projects in the PPG. The specific aims are: 1. Acquisition of normal and CF tissue. 2. Generation of in vitro models of human airway epithelia. 3. Characterization of in vitro models and native epithelia. a. Electrophysiologic analysis. b. Morphologic evaluation. c. Genotyping of CF cells. 4. Research and development of new methods and models for the study of gene transfer, airway epithelial, cell biology, and submucosal glands. 5. Production of cultured cells for investigators in the PPG. 6. Development of a cryogenic bank of airway epithelial cells. 7. Teaching investigators at the University of Iowa and other institutions the methods for developing in vitro model systems. 8. Record keeping relevant to tissue acquisition and cell culture. 9. Obtaining approval from regulatory committees and record keeping for cell and animal studies. 10. Provision of cells, plasmids, and viruses to investigators at other institutions. This Core brings the expertise of a highly motivated and technically sophisticated staff to the benefit of the PPG investigators. As a result, it allows PPG investigators to focus their unique expertise on questions of high relevance to CF gene transfer.